Process of treating hydrocarbons



J. R. M CONNELL PROCESS OF TREATING HYDROCARBONS June 29 1926.

Filed July 27, 1925 G as cum; SToRneE Cause STORAGE TA K L- Jvwmflow 5' $0M R.M DNNELL.

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Patented 29, 1926.

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Application filed m 27. 1925.: Serial at. 46,487;

My invention relates to the treatment of light hydrocarbons preferably distillate Y hydrocarbons to obtain a gasoline which is substantially free from color or what is known as a clear product of a 25 plus color by Saybolt chromometer. This process is known as the fixation process for refining gasoline. This application is a continuation inpart 'of Ser. No. 735,650, filed Sept. 3, 1924.

Gasoline refined from. crude oils such as Santa Fe Springs, Huntington Beach or Signal Hill, if carried to a finished product by straight distillation without clay or acid treatment, has the peculiar property, when exposed to daylight, of taking on a discoloration which n'iay be pink, yellow 'or light chocolate, *and' the reaction is more "rapid when sunlight is directed 'upon' the liquid; for instance, when the untreated gasoline from these crudes' is placed in the.

so-called visiblepump. This discoloration is i found objectionable by the trade, which demandsc'a clear, colorless product.

- The 'present methods' of treatmg gasoline characteristics mentioned in the second paragraph to obtaina colorless product, is

e as

:Nvhere acid is omitted, the color of'thegas:

'ferentiate between the oldprocesses and the -new. e f The acid and clay treatments mentioned. above entail considerable ex'trahandling, ex-, tra apparatus and a loss in. the volume ofgasoline,' and, in addition, often when re-' distillation does not follow the acid treat-- ment. a portion: of the acid remains-in the gasolinesdluble as sulphonic acid, which as an'injurious effect on the motor. The 6 0 acid also removes from the gasoline a pore :tion of the aromatic hydrocarbons, which are valuable products in the gasoline, due, to

theirfaculty of eliminating to a certain ex-" tent, detonation in the motor. It is known that gasoline (of the characteristics" men-' tionedinthe-secondparagraph) treated with clay alonehas turned adecided', on exposure to light. v

- Broadly stated my process com rises treating ig late hydrocarbons 'containin a compound sensitive to daylight to pro uce a product substantially freefrom color and, not sensi tive to daylight by exposing the distillate- .hydrocarbons, containing the sensitive compound, ,to daylight rays to fix the color or ht hydrocarbons. suchas istilr complete the color reaction to its maximum, and thereafter removing. the .discoloring compound'preferably by distillation, y I have discovered that if a distillate hy drocarbomfor example, ahydr'ocarbon of low boiling point, from the crudes m n- .tioned, has its discoloring. compound completely fixed and is then redistilled, there is obtained-a clear product which permanently .remains'in this condition and is a satisfa'c- In other tory commercial commodity. words, referring to the finished product, the

in terms of the Saybolt'chromomete'r; The Saybolt chromometer method is setforth on page 31 of Technical Bulletin 323, U. S. Department of Interior and is entitled, Speci- 'fications for petroleum products: Preferably, I fix the 'color'of the distillate hydrocarbons in thenaphtha distillate stage by exposure to daylight or sunlightrays, and

the. fixed sensitive portion, which isprobably of an organic sulfur composition-,be-

comes non-volatile and. therefore remains in the residue on distillation. This, it is' gasoline will have a 25" plus color measured l thought, accounts for the freedom from color in the finished gasoline on'redistilla- .tion.

The subjecting of the distillate hydrocarbon to the action ofdaylight until com plate-color change has taken place, is what is referred to as complete fixation.

If the discoloring. compound contained in h the distillate hydrocarbon has not been entirely. fixed, due to insuflicient exposure tof daylight, the resultant gasoline after dis-- tillation will be clear but will go dfl-I color I when exposed to daylight to a degree pro-I portional to the amount ofdlscoloring compound which has not been fixed.' This is" what is referred to as; partial fixation. In this case the gasoline ,is again subjected to daylight. exposure, andif need be, redistilled to obtain a permanently colorless'gasoline. Usually, after. distillation of the partially fixed. distillate hydrocarbon the resultant asoline becomes pink on exposui'e to dayight. If the pink is only of a faint hue it ma be bleached to a very faint tinge of yel ow, which in some cases may be allowed to remain in the marketable gasoline. However, no gasoline which has been partially fixed and then bleached, ever turns out as ood in color as that which'is completely fixed and then distilled. In case of partial fixation, a portion of the sensitive discolor ing compound is still volatile and is carried over with the finished gasoline:

The naphtha distillate hydrocarbon from the crude, on exposure to light, which is at first water white, may change in color to green, pink, brown or chocolate, and finally to a yellow. The heavier-the distillate the greater the discoloration, due to light action.

For a complete understanding of my process of treating hydrocarbons and the a paratus therefor, reference is made to e accompanying drawing, the figuresof which are more or less diagrammatic. in which:-

erably 15 ft. high Fig. 1 shows the flow sheet of-the product from the crude tank to the finished gasoline storage tank;

Fig. 2 is a plan view of the top or deck of the fixing tank; 1

Fig. 3 is a side elevation of the fixing tank;

Fig. 4 is a plan view of the storage tank; and

' Fig. 5 is a side elevation of a storage tank, indicating how the windows are placed thereon and the means for covering the windows when it is desired to shut off the daylight.

The apparatus shown in Figures Nos. 2 and 3 comprises a 2000 barrel tank F, prefand thirty feet in diameter,

and has inserted in the deck (G) windows (D) of prismatic glass. This glass is held in ordinary wooden frames bolted securely to the iron deck of the tank, so the tank at all vttimesis practically air-tight. A secondary adjunct is a float (c) which raises a swing line (E) in the tank to a point about six inches below the liquid level. Hence, in drawing from the tank that liquid, nearest the surface, is always taken, and consequently that which has been subjected to the greatest light action. (B') is the discharge conduit and (A) is the inlet conduit.

The greater the number of windows in the tank deck (G), the greater will be the lightexposing surface and consequently the reaction inside of the tank will occur more quickly. I have found that when the light surface occupies approximately twenty per cent of the tank deck surface, satisfactory results are obtained.

On the decks of the fixing tanks are placed conventional sprinklers which are used in warm. weather for keeping the tank cool and to overcome radiation caused by the reflectors. The storage tank (H) shown in figures make the finished ously or in batches.

4 and 5 has on the deck I, a series of windows (J), each ofwhich has attached thereto a ap (K) of the rubber sheeting or similar material. The flaps (K) may be thrown over the glass when it is desired to shut out the dayhght rays. (L) is the inlet conduit and (P) is the outlet conduit.

Referring to Fig. 1, in carrying out the process the naphtha distillate coming from the crude'stills 2, is run by gravity into either of the fixing tanks 3 or 4. When using a tank 3 or 4 of type (F) as shown in Figs. 2 and 3, 1

tillate has been entirely fixed in color, the

distillate is pumped to the re-run stills 5 to be re-dist1 led to the proper end point, then into tank 6, at which point itis tested and if of proper test, is transferred to storage tank 7. If fixation has been completed in tanks 3 or 4, the gasoline obtained in tank 6 will be 25 plus in color and of a definite color stability.

The proper operation of" the process de-.

pends primarily upon the construction of the xing tanks (F), and the insurance ofcomplete fixation of color before distillation to asoline. The naphtha distillate may be either distilled from the conventional horizontal still, with or without towers, or the pipe still, and either continu- After fixing the color, redistillation may take place in steam stills, horizontal combination or any other proper distilling device. I

The term naphtha distillate as used above is, of course, to be given the customary meaniri accorded it by those skilled in the art. e B. gravity and the boiling point may vary considerably. As an illustrative example the naphtha distillate, may be obtained as follows, but .it is obvious that I do not limit myself to a naphtha only obtained With an average temperature of 65 degrees, satisfactory results have been obtained.

' \Vhen the naphtha first leaves the condenser of a plus color, under ordinary exposure to daylight.

The color fixation may also. be accomplished by use of an artificial light such as the ultra violet ray.

My process is also applicable to the treatment of cracked gasoline. In the cracking of fuel oil to produce motor fuel or gasoline,

the first step is, usually, to produce a pressure distillate." This pressure distillate contains the light fractions of gasoline which are obtained by subsequent distillation of the pressure distillate. The gasoline so obtained is very susceptible to the action of daylight, usually taking on a rich yellow or reddish-yellow color. In most cases, this color is eliminated by treatment with an acid such as sulfuric, or by treatment with fullers earth. I find that by subjecting the raw gasoline produced by cracking to the prolonged action of daylight rays, a large percentage of the color becomes fixed. Upon subjecting this fixed cracked gasoline to aprocess of distillation, approxlmately 70% clear 25 plus color gasoline may be; obtained as a distillate. The balance of thedistillate will contain some color which can be removed either by acid or clay treatment.

The application of my fixing process to cracked gasoline, dispenses with the necessity of treating a large percentage of the cracked gasoline with either acid or clay.

Gasoline distilled from partially fixed naphtha distillate may be exposed to daylight rays through diffused glass and the color thereby completely fixed. In the claims, the term,"light rays is intended to cover daylight rays, ultra violet rays orrays of any character which will function to substantially completely fix-the I color of the sensitive discoloring compound present in the hydrocarbon treated.

This application is a continuation in part of McConnell application Ser. No. 735,650, filed Sept. 3, 1924.

I claim 1. The process oftreating light hydrocarbons containing a sensitive discolorin compound to produce water-white light carbons substantially free from color and having a definite color stability, comprising exposing the light hydrocarbons for a period of time to the sole action of light rays to completely fix the color of the sensitive discoloring compound and thereafter distilling the so treated light hydrocarbons.

2. The process of treating light hydrocarbons containing a sensitive discoloring compound to produce a Water-white gasoline substantially free from color and having adefinite color stability, comprising exposing the light hydrocarbons for a period of time.

to the sole action of light rays functioning to completely fix the color of the sensitive discoloring compound and thereafter distilling' gasoline from the so treated light hydrocarbons.

The process of treating light hydrocarbons containing a sensitive discoloring compound to produce a water-white gasoline substantially l'ree from c0lor and having a definite color stability, comprising exposing the light hydrocarbons for aperiodof time to the sole action of daylight rays to completely fix the color of the sensitive discoloring compound and thereafter distilling gasoline from the so treated light hydrocarbons.

=4. The process of treating naphtha distillate containing a sensitive discoloring compound to produce a water-White gasoline substantially free from color and having a definite color stability,.comprising exposing the naphtha distillate for a period of time to the sole action of light rays functioning to completely fix the color of the sensitive discoloring compound and thereafter distilling gasoline from theffixed naphtha distillate.

5. The process of treating naphtha distillate containing a. sensitive discoloring compound to produce a water-white gasoline substantially free from color and having a definite color stability, comprising exposing the naphtha distillate to the sole action of dayli ht rays for a. period of time to completely the color of the sensitive discoloring compound and then distilling gasoline from the fixed naphtha distillate.

6. The processof'treating naphtha distillate to produce a' stable 25 plus color com prising subjecting the naphtha distillate to liydrothe sole action of daylight rays to completely fix the sensitive discoloring compounds prior to distillation of said-distillate and thereafter distilling water-white gasoline from the fixed naphtha distillate.

In testimony whereof he hereunto aifixes his signature.

JOHN ROBERT MGCONNELL. 

